The objectives of research proposed here are continuations of those pursued by this laboratory over the past several years. (1) To apply biochemical and enzymological methodologies in the identification of molecular lesions in human blood cells associated with acquired or inherited human disease. (2) When such are identified, to define the clinical syndrome, conduct family studies where inherited lesions are involved and in such instances determine the mode of inheritance and the expression of the lesion in heterozygotes, hemizygotes, and homozygotes. (3) To determine the effects of the lesion on metabolic intermediates nucleotide pools, and cell morphology. (4) To extrapolate information obtained into further knowledge re normal regulation of metabolism. (5) To relate information derived from inherited "experiments of nature" to physical and kinetic characteristics. (7) To develop methodology and expand existing techniques applicable to metabolic studies of human blood cells. Established technology in the laboratory permits assay of all enzymes of anaerobic glycolysis the hexose monophosphate shunt, many enzymes of nucleotide metabolism enzymes of glutathione synthesis and metabolism, and a considerable number of non-glycolytic enzymes including several pertinent to membrane phospholipids. (8) To utilize the spectrum of methodology available to study metabolic effects of reactive compounds potentially present in vivo or in the environment. Example: Effects of sulphydryl modifiers on enzyme catalysis, kinetics, thermostability; effects of lead. (9) To identify isozymes with differing metabolic properties and capabilities. (10) While erythrocyte metabolism has been a predominant concern, laboratory interests will not be confined to this cell type. For example, nucleotide metabolism in "B" or "T" lymphocyte cell lines is being studied in relation to immunodeficiency states associated with disturbed nucleotide metabolism and enzyme deficiency states.